Liquid cooled disk brake arrangement



1964 B. MALONEY ETAL LIQUID COOLED DISK BRAKE ARRANGEMENT 5 Sheets-Sheet1 Original Filed May 20, 1958 1964 B. MALONEY ETAL LIQUID COOLED DISKBRAKE ARRANGEMENT Original Filed May 20, 1958 5 Sheets-Sheet 2 HiEZENTORS. 6 22(L2t/ 6 071-2 Feb. 18, 1964 B. MALONEY ETAL 3,121,477

LIQUID COOLED DISK BRAKE ARRANGEMENT Original Filed May 20, 1958 3Sheets-Sheet 3 Maw @RMW R United States Patent Maloney, Gary, Russell G.Altherr, Munster, rind, and Robert D. Blew, Matteson, Ill., assignors toAnn rican Steel Foundries, Chicago, ill., a corporation of New Eersey@rlginal application 2t), 1958, filer. No. 735,644, now Patent No.3,ti22,367, dated Pets. 27, E 62. Divided and application Mar. 24, 3961,Ser. No. 98,153

i @iaims. Il. 188-72) This invention relates to brakes and, moreparticularly, to off-wheel or disk type brake arrangements. Thisapplication is a division of our copending application for Liquid CooledDisk Brake Arrangement, Serial No. 736,644 filed May 1958, now PatentNo. 3,022,867.

The invention comprehends an improved off-wheel brake arrangement of thetype wherein friction walls of brake members are cooled by thecirculation of liquid coolants in the members.

As is lmown to those familiar with the brake art, certain of the disk orclutch type brake arrangements comprise fixed and axially movablestators, disposed on opposits sides of a rotatable member or disk forengagement therewith. Additionally, these brake arrangements usuallyinclude an actuating member, engageable with the axially movable statorand operable to force the stator against the disk, which in turn, isforced against a fixed stator, whereby frictional engagement between thestators and the disk effects the deceleration of the disk.

Although there are numerous ways in which an axially movable stator canbe urged into engagement with a related disk or friction member, acommon method employed in the past has been the use of a hydraulicallyactuated annular piston, such as that disclosed in Patent No. 2,778,451,issued January 22, 1957, to R. G. Friedman.

The use of an annular piston of this type creates many problems inconnection with the operation and maintenance of disk brakes. Aprincipal objection to this type of actuating means, is that in theevent that the piston becomes scored or otherwise damaged, it becomesnecessary to disassemble the entire device to replace the annularpiston. This is both time consuming and expensive secause in thesearrangements the annular piston forms a major component element of thebrake mechanism.

Another disadvantage of the single annular actuating piston is that inthe event of piston failure for reasons other than leakage of hydraulicfluid from the system, the entire brake is rendered inoperative;whereas, when a movable stator is actuated by a plurality ofcircumferentially spaced power cylinder pistons, if one piston fails tofunction, the brake can still be actuated by the remaining powerpistons.

Yet another disadvantage of the single annular actuating piston is thatafter a relatively limited period of use, any uneven wearing of elementsmay tend to cause the piston to cock or angle relative to its axis ofoperation. The chances of this angling are minimized Where the movablestator is moved by the application of equal forces exerted by separatepower cylinder pistons spaced circumferentially from each other.

in view of the above, it is thereto e a primary object of this inventionto provide a disk brake arrangement wherein a rotatable disk is engagedbetween a pair of stators, one of which is moved axially into engagementwith the disk by a plurality of separate hydraulic pistons spaced circumerentiall of the stator from each other.

Another important object of the invention is to provide an arrangementof the type described, wherein the fric- Ice tion surfaces of the diskor rotatable friction member are pr ented by a floating friction block,carried by the fri 'on member for rotation therewith and for axialmovement relative thereto.

A further object of the invention is the provision of a brake statorhaving a relatively thin wall presenting another friction surfaceengageable with a rotatable element to be braked and having an internalchamber adapted for the circulation of a coolant liquid therethroughagainst the inner surface of said wall.

A more specific object of the invention is the provision of means toincrease the pressure value of the coolant liquid in the stator chamberat a rate in direct proportion to the rate of increase of the pressurevalue of the liquid in the hydraulic power brake actuating system inorder to maintain approximately equal pressure values on op posite sidesof the stator friction wall and thereby minimize the amount of localizedstress exerted on the wall.

These and other objects of the invention will be apparent from anexamination of the following descriptions and drawin s wherein:

FIGUI l is a fragmentary front elevational view of a brake arran ementembodying features of the invention, with portions of the structureshown in vertical section tahen on line 3-1 of FEGURE 2;

FEGURE 2 is an end elevational view of the structure illustrated in alGURE 1, with portions of the structure shown in vertical section takenon line Z2 of FIG- 3 and 4 are similar to FEGURES l and 2, but includeonly such portions of the structure as are necessary to illustrateanother form of the invention;

FlGURE 5 is similar to FEGURE 3, but illustrates still another form ofthe invention;

FiGURE 6 is a fragmentary side elevational view, partly in verticalsection, illustrating another feature of our invention;

FIGURE 7 is a schematic diagram illustrating brake actua ng hydraulicfluid and coolant fluid circuits embodying yet other features of theinvention;

FIGUPE 8 illustrated the choke valve between the brake a ating circuitand coolant fluid circuit shown in EEG 7; and

FIGURE 9 is a vertica FZGURE it will be understood that certain elementshave been intentionally eliminated from certain views, where they areillustrated to better advanta e in other views.

Referring now to the drawings for a better understanding of theinvention, and particularly to the upper half of PEGURE r, it will beseen that the brake arrangement, embodying features of the invention, isshown as attached to or mounted on an axle housing, indicated generallyat of a vehicle, not shown.

The brake mechanism includes a generally cylindrical hous g or brakeframe, indicated generally at 12, comprising inner and outer cylindricalwalls 14- and 16, preferably formed integrally with and extendingoutboardly from an annular plate 18 having a central aperture 243 forreceiving the axle housing to. An annular cavity 22 is defined betweenthe inner and outer cylindrical walls 14- and 36.

Although the brake frame 12 may be mounted on the axle housing invarious ways, a preferred form is shown in FIGURE 1 of the drawings,where it can be seen that plate is provided with a pair of inboardlyextending shelves 24 (only one of which is shown), spaced from eachother on opposite sides of the vertical center plane of the frame, eachof the shelves being supported by a inclined arm 26, interconnecting theinboard section taken on line 9-9 of preferably extremity of the relatedshelf with the lower portion of plate 18 and preferably integraltherewith.

The axle housing may be provided with a pair of outwardly extending,centrally disposed flanges or lugs 28 (only one of which is shown), towhich are secured portions of an elliptical spring 39. The shelves 124of the brake frame are disposed to fit under and engage the undersidesof the lugs 28, and the frame is secured to the housing by means of apair of U bolts 32 (only one of which is shown), spaced on oppositesides of the axle from each other and disposed to surround the springsand extend through axle housing flanges 2d and shelves 24. Each U boltmay be retained in position by a pair of nuts 36. In addition tooffering support for the shelves, the arms 26 serve to transmit brakingtorque from the brake frame 12 to the axle housing lit.

Again referring to FIGURE 1 of the drawings, it will be seen that thereis attached to the axle housing, outboardly of the brake frame 12, awheel 38. Although the actual mounting of the wheel on the axle is notshown in detail, as it does not form an essential part of this invention, it will be understood that the wheel is rotatable relative tothe fixed axle housing it Secured to the wheel for rotation therewith inany desired manner, as by means of stud bolts til, is an annular disksupport 42. At the inboard side of its outer periphery, disk support 42is connected to an outer peripheral portion of an annular frictionmember or disk In the embodiment illustrated in FIGURE 1, it will beseen that the connection between disk 4 and support 42 comprises aplurality of pins 46 attached to support 52 and disposed to extendthrough both the disk and sup port, in a direction parallel to theirrotational axes, in such a manner as to accommodate the axial movementof the disk relative to the support, the axial position of which isfixed relative to the axle housing of the vehicle.

In order to effect a closure of the gap between the outboard end of thebrake frame wall it? and the inboard end of disk support 4-2, andthereby prevent dirt and other foreign matter, such as ice and snow,from entering brake frame cavity 22, there may be provided a sealingdevice, comprising a pair of oppositely facing annular, U-shaped insection, elements 43 and Sit secured to disk support pins 46 and brakeframe wall by bolts or machine screws 49 and 51, respectively. Theelements 48 and 50 may be provided with annular abutting pads 52, whichpermit relative rotation therebetween. To pro vide a dust seal betweenthe rim of Wheel 35 and the brake enclosure, element 4 3 may be providedwith an an nular sealing ring 53 attached thereto and disposed tosurround the element.

A coil compression spring 55 sleeved on screw 49 and compressed betweenthe outboard side of element 48 and a shoulder 57 presented by pin as,serves to maintain the pads 52 of the respective elements 48 and 56' insnug engagement with each other even during relative rotationtherebetween.

Still referring to FIGURE]. of the drawings, it will be seen thatadjacent the inboard and outboard sides of disk 44, there are provided apair of stators 56 and 5%, respec* tively: Inboard stator 56 is axiallymovable relative to the axle housing and brake frame, and outboardstator 58 is fixed relative to the axle housing and brake frame.

Axially movable stator 56, is annular in shape, having a central openingthrough which extends axle housing it) and portions of stator 58. Stator56 may be supported from the brake frame 12 by means of a pair of links{it pivotally connected at opposite ends by pins 62 and 6 5 tooutboardly and inboardly extending lugs 65 and 68, presented by thebrake frame and stator, respectively.

Still referring to FIGURE 1 of the drawings, it will be seen that stator56 is somewhat rectangular in section and has a pair of coolant liquidinlet openings or cavities (only one of which is shown) located atdiametrically opposed sides thereof. The upper opening 7% is an inletopening. The lower opening is an outlet opening but is not shown inFIGURE 1 as this view is not a symmetrical section view. On its inboardside stator 56 is provided with a pair of inlet and outlet ports '71 and71a cornmunicating with the respective inlet and outlet openings 7% ofthe stator. Only port '71 is shown in FIGURE 1, although both ports areshown in FIGURE 2. The inlet and outlet openings both communicate with aplurality of annular coolant liquid grooves or chambers 33 which arespaced radially from each other by a plurality of annular ribs 85.

The outboard wall of stator :76 is preferably in the form of adetachable friction plate '72, secured to the stator in any desiredmanner as by machine screws 74. Plate 72 is preferably formed of a thinsheet of a metal such as copper which has a relatively high thermalconduction capacity, and is adapted to close chambers 83 on one side andto present on its outboard side, a friction surface 76 engageable withfriction surface 73 presented by a brake liner 80 attached to theadjacent side of disk 44.

Stator 58 comprises a cylindrical wall 82 sleeved over the axle housingit) and abutting the inner wall 14 of the brake frame, preferably ininterlocking relationship therewith, and a radially outwardly extendingstator ring or head 84, formed in much the same manner as stator 56, andcomprising an inlet opening 86, corresponding to inlet opening 7ft instator 56, and an outlet opening, not shown in FIGURE 1 butcorresponding to the outlet opening of stator 56.. The inlet and outletopenings of fixed stator 58 also communicate with a plurality of annulargrooves or chambers 83 radially spaced from each other by a plurality ofannular ribs 85. Stator 53 is also provided with an annular preferablycopper friction plate 72 secured thereto by screws 7d.

Fixed stator wall 82 is provided adjacent its inlet and outlet openingswith a pair of axially extending passageways or channels, only the inletpassage way 83 being shown in FIGURE 1, which communicate with alignedinlet and outlet passageways only the inlet passageway 913 being shownin FIGURE 1, in brake frame wall 14. Wall 14 is provided with a pair ofinlet and outlet ports 92 and 92A communicating with respectivepassageways 90. In FIGURE 1 only inlet port 92 is shown, while in FIGURE2 both are shown.

Fixed stator wall 82 and brake frame wall 14 are maintained in snugabutting relationship with each other, and against an axle housingshoulder 94, by means of a large nut 96, threadably received on the axlehousing at the outboard side of the stator.

As best seen in the lower pontion of FIGURE 1, heat ing stator 56 isurged into engagement with disk 44, which in turn is urged against fixedstator 58 by means of a plurality of hydraulic cylinders 98, located inbrake frame cavity 22, and secured to plate 18 thereof in any desiredmanner, as by means of bolts or screws 10%. There are preferably fourhydraulic cylinders 98, only one of which is shown in FIGURE 1, spacedcircumferentially of the frame or stator from each other at equaldistances. Each of the cylinders comprises a piston 102, engageable withthe inboard surface 104 of floating stator 56. In order to release thepiston from the stator when the brake is in an applied position, theremay be provided a release mechanism (not shown) of any desired type.

Power cylinders 98 are energized prefa-rably by hydraulic fluid,supplied from any type of source not shown in detail but indicateddiagrammatically in FIGURE 7 at 116. All four cylinders 93 may beconnected to the hydraulic fluid supply line 113. The hydraulic fluid istransported from the line 118 through a port 126 (FIG- URE 2) into aT-shaped manifold connection 122 located in brake frame cavity 22 andfrom there through lines 124- to the adjacent cylinders 98 and thencethrough the cylinders to the remote cylinders 98 through line 126. Asseen in FiGURES 1 and 2, the cylinders and piping interconnect ng thecylinders and the hydraulic circuit are all disposed within brake framecavity 22. Thus, as the master cylinder 116 is actuated in any manner,as by brake lever 12%, the master cylinder energizes the individualcylinders 98, causing their pistons 1% to engage adjacent movable stator56 and urge the stator against the disk 44, causing the disk to moveaxially in an outboard direction toward the fixed stator 53, whereby thedisk is compressed between the movable and fixed stators.

As is known to those familiar with the brake art, great quantities ofheat are generated by the frictional engagement between related frictionsurfaces of the stators and disk during normal braking operations. Inorder to effect the rapid dissipation of that heat it is highlydesirable to provide some method to cool the friction surfaces andthereby prevent the engaging parts from burning out.

This has been accomplished by the provision of the annular chambers 83in the stators and means to circulate a coolant liquid, such as water,therethrough and against the inner surfaces of the friction plates 7 2.

Still referring to FIGURES 1 and 2, it will be seen that within theannular cavity 22 of the brake frame 12, there is provided a pair ofupper and lower coolant liquid inlet and outlet manifolds 134i and 132provided at corresponding ends with Y type connectors '134 and 136,respectively.

As best seen in FIGURE 2, connector 134 includes a pair of pipe lines134:: and l d]; communicating with inlet ports 71 and @2, respectively.Connector 136 includes a pair of pipe lines 336a and 136b communicatingwith outlet ports *la and 92a, respectively. Lines 134a and 136a areflexible lines which accommodate axial movement of stator s.

The manifolds 13d and 132 are provided at their opposite extremitieswith ports 13% and 144), respectively, which communicate with pipe line142 of a coolant liquid circuit which in turn includes a choke valve144, a reservoir 146, and a constant volume pump 148. The details of theliquid coolant and hydraulic circuits are shown in the schematic diagramof FIGURE 7 and will be described in detail in a later portion of thespecification.

Referring now to FIGURES 3 and 4 of the drawings, it will be seen thatthere is illustrated therein a slightly modified form of the invention.In this arragement, a disk 44a, similar to the previously descibed andillustrated disk 44, is carried by a disk support 42a by splinedconnection which accommodates axial movement of the disk relative to thesupport in much the same manner as does pin 6 in the previouslydescribed embodiment. As best seen in FIGURE 4, the outer periphery ofdisk 44a is provided With cut-out or notched axially extending groovesor slots 1% spaced circumferentially of the disk from each other topresent therebetween radially outwardly extending lugs 152. In a likemanner, disk support 42a is provided at its inboard edge with aplurality of axially extending projections 15 spaced circumferentiallyof the support from each other to define therebetween a plurality ofaxially extending slots 155.

Disk 44a is carried by support 4212, for rotation therewith and foraxial movement relative thereto, with disk lugs 152, received withinsupport slots 155', and with support projections 154 received withindisk slots 150 to provide snug splined engagement between the disk andsupport. The support is maintained in engagement with the disk by meansof a plurality of shoulder screws 153 located and spacedoircumferentially from each other and disposed to extend throughalternate disk lugs 152 and into support 42a.

As best seen in FIGURE 3, there is ample clearance provided in slot 155between the disk lugs 152 and the support 42a, to accommodate axialmovement of the disk relative to the support. Screws 158 are preferablyshoulder screws, threadably received within the support. A plurality ofwashers 160 are provided between the head of the screws and the inboardsurface of the disk to limit inboard movement of the disk, relative tothe support. Additionally, the support may be provided with a pluralityof internal axially extending bores 162, in which are disposed coilcompression springs 164, compressably interposed between the support andthe outboard surface of the disk. The springs E64 serve as a releasemechanism to urge the disk in an inboard direction away from the fixedstator when the brake is in an inoperative or a non-applied position.

Now referring to FIGURE 5 of the drawing, it will be seen that there isillustrated therein a modified form of the invention. The primarydifference between this embodiment and the previously describedembodiments of the invention is that in this embodiment, a rotatablefriction member or disk 44c is rigidly secured to the disk supportmember 42c by means of screws 16d and washers 168, so that axialmovement between disk 4 and disk support 420 is prevented. Disk 44c maybe a one-piece article or, if desired, may, as illustrated in FIGURE 5,comprise a plurality of annular plates 17d, secured to each other in anydesired manner as by rivets 1'72, only one of which is shown, to providea unitary brake ring having a plurality of circumferentially spacedopenings 1'74 (only one of which is shown) within which are carriedfloating brake liners preferably formed of a friction composition of thetype normally employed for brake linings. Liners 176, although rotatablewith disk 44c are free for movement relative thereto, the extent of suchaxial movement being limited only by the friction surfaces of themovable and fixed stators disposed adjacent opposite sides of the disk.The operation of this embodiment is similar to that of the previouslydescribed embodiments wherein the pistons of the hydraulic cylindersurge the movable stator axially in an outboard direct-ion, causing it toengage floating liners i176 and compress them against the fixed stator58.

FEGURE 6 of the drawings illustrates another feature of the invention,wherein friction plates 72a of the fixed and movable stators (only thefixed stator being shown, as the arrangement in the movable stator issimilar) can be detachably secured to the ring or head 34a of the statorin order that they may be readily removed with a minimum of time andeffort. In this arrangement, the head or ring of the stator, presentsadjacent its inboard edge, a pair of annular grooves 17% adapted toreceive the outboardly extending oil-set annular flanges of plate 72a,which has been provided with a pair of inwardly extending rims or lipsThus, by virtue of the flexibility of the metal in the plate 7212, itmay be snapped in position over the head of the stator with the inwardlyextending rim 132 tightly disposed wthin annular groove 173 to closecoolant liquid chamber In order to insure a fluid-tight fit between theplate an the head of the stator, a pair of conventional O ring typeseals llid, disposed within recesses 136 of the stator head, may beprovided. The seals serve to prevent the fic-w of any liquid between theengaging surfaces of plate 72a and stator head $411 and thereby retainit in chamber 833a.

As was previously mentioned, it is highly desirable in liquid cooledbrake arrangements of this type to form the stator friction walls,plates 72 in FIGURE 1 or 72a in FIGURE 6, of a relatively thin sheet ofmetal having a relatively hi h rate of thermal conduction because themore rapidly the heat caused by frictional contact can be transmitted tothe coolant liquid, the more rapidly the heat can be dissipated by thecoolant liquid. A serious problem resulting from the use of a thin metalplate of the appropriate composition, such as copper, is that thevarying forces exerted on opposite sides of the metal by the brakingaction and liquid coolant, respectively, tend to deform the plate andthereby prevent perfect frictional engagement by the braking surfacesalong a smooth flat surface. Also, the force of the liquid coolant, iftoo great, can cause the plate to separate from the stator head andpermit the coolant to leak out of the circuit, thereby greatlyimpairing, if not completely preventing, proper functioning of thebrake. Although, in the embodiment of the invention, shown in FIGURE 1of the drawings, the stator head is provided with a plurality of ribs85, which form the radially spaced annular grooves 83 and which alsoserve to offer additional support for the plate 72, it would be evenmore desirable to have an arrangement such as that illustrated in FEGURE6, wherein the extra supporting ribs (55 are eliminated and the entirecoolant chamber 834: is completely open, so that the coolant liquid ifree to contact all of the inner surface of plate 72a. in order topermit such an arrangement, it is necessary to equalize the stresses orressures exerted on opposite sides of the plate by the coolant liquidpessure and the brake pressure, respectively.

Turning now to FlGURE 7, a schematic diagram illustrating a novelpressure equalizing arrangement, it will be seen that the coolant liquidpasses out of port 140 through line 142 and back to the inlet port 138,via choke valve 144, reservoir 145, and constant volume pump M8. Be ausethe purpose of choke valve 144 is to increase the pressure in thecoolant liquid circuit in direct proportion to that of the pressurevalue in the hydraulic circuit, it is afforded communcation withhydraulic circuit line 113 by means of auxiliary line 18 6.

FIGURES 8 and 9 are top plan and vertical sectional views, respectively,of choke valve 144 (the position of which is inverted in FIGURES 8 and9), which is preferably annular, comprising a central cylindricalhousing or body 133, having an internal longitudinal extending bore 190Within which is disposed a piston The piston is retained within the boreby means of a bonnet or cap 194, threadably received within one end ofthe bore. At one end, the bore presents a cylindrical cavity or chokechamber 1%, which communicates with a pair of transversely extendingcoolant inlet and outlet ports 2G6) and 198, respectively. The piston ismovable into chamber 196 to restrict the flow of liquid coolant in theline 142 from the coolant inlet port 2% to the coolant outlet port 198.At the end of the piston remote from .charn'oer 195 the piston isprovided with a cylindrical extension 202, slidably received within acoaxial bore 2%, within cap 194. In order to effect a liquid-tight sealbetween extension 2&2 and axial bore 2'34, one or more O-ring type seals2556 may be provided. At its outer extremity, bore 2% is provided with aport 2% which communicates with pipe line 186 leading to the mainhydraulic circuit line 118.

Thus, it will be understood that as the pressure builds up in thehydraulic circuit line 118, the pressure is transmitted through line 186and port 2% to extension 202 of the circuit valve piston 192, causingthe piston to move upwardly and close or restrict the size of chokechamber 1% and thereby decrease the flow of coolant liquid through thechoke valve. Inasmuch as pump 148 is a constant volume pump, the coolantliquid is being forced into the circuit from reservoir 146 at a greatervolume rate than the rate of return, so that the pressue value in thecoolant liquid circuit is increased at a rate in direct proportion tothe rate of increase of the pressure value of the hydraulic circuit. inthis way, the forces exerted on opposite sides of the plates 72 or 72aare maintained in approximately equal relationship to minimize oreliminate any stress on the plates. In order to prevent the piston 192from moving into and restricting the opening in choke chamber 1% when itis not necessary, a coil compression spring 21% may be interposedbetween a flange 212, presented by the piston El 2 and an off-setportion or shoulder 214 presented within bore 1%.

in View of the above, it will be seen that We have provided. aninvention comprising a highly efiicient, compact liquid cooled diskbrake arrangement, wherein a rotatable friction member to be braked iscompressed between 21 pair of stators which are actuated by a pluralityof circumferentially spaced pistons of independent hy draulic cylindersand wherein the friction surfaces of the stators and disk areefficiently cooled by a novel cooling system, which is formed andadapted to afford the maxi mum amount of thermal dissipation of the heatgenerated by the frictional resistance in the braking operation.

We claim:

1. In an oil wheel brake arrangement for a vehicle having a wheel andaxle assembly, the combination of: an annular disk support secured tosaid wheel for rotation therewith; a disk disposed inboardly of saiddisk support and presenting a pair of friction surfaces; a plurality ofpins having corresponding ends attached to said disk support, said pinsextending through complementary openings of the disk to accommodateaxial movement of said disk relative to said support and interlock thedisk therewith for rotation with the wheel; a brake frame nonrotatablymounted around said axle, inboardly from said wheel, said brake frameincluding an annular plate extending radially outward from said axle,said annular plate having a cylindrical wall formed integrallytherearound and extending in an outboardly direction therefrom; a firstannular ring secured around the outboard end of said cylindrical wall; afirst abutting pad disposed around and fixed to the outboard end of saidfirst annular ring; a second annular ring disposed outboardly from saidfirst annular ring; a second abutment pad secured to the inboard end ofsaid second annular ring; a plurality of screws extending throughapertures in said second annular ring and extending into the inboard endof said plurality of pins; a plurality of compression spring meanssleeved on respective screws between said second annular ring and saidinboard end of said pins for urging said second annular ring inboardlyso as to urge said second abutment pad into engagement with said firstabutment pad to provide a seal therebetween; an annular sealing ringcompressed between said second annular ring and said Wheel to provide aseal therebetween; and means provided on the brake frame fordecelerating rotation of the friction surfaces of said disk.

2. In a brake arrangement for a Wheel and axle assembly, the combinationof: an annular disk support secured to said wheel for rotationtherewith; a plurality of pins having corresponding ends attached tosaid disk support; a disk presenting a pair of axially movable frictionsurfaces, said pins extending through openings of said disk toaccommodate axial movement of said disk relative to said support and tointerlock the disk for rotation therewith; a brake frame non-rotatablymounted around said axle; means mounted on said frame for braking thefriction surfaces of said disk, said frame having a wall, a firstannular ring secured to said wall, a first abutment pad secured to saidring, said first pad presenting a first abutment surface; a secondannular ring connected to the support for rotation therewith; a secondabutment pad secured to said second annular ring and presenting a secondabutment surface; a plurality of resilient means operatively connectedto said annular ring for urging said sec ond abutment surface intoengagement with said first abut merit surface to provide a sealtherebetween; and an anular sealing ring compressed between said annularring and said wheel to provide a seal therebetween.

3. In a brake arrangement for a wheel and axle assembly, the combinationof: a brake frame non-rotatably mounted around said axle; an annular endwall integrally formed radially outwardly on said brake frame to partlydefine a chamber in said brake frame adjacent said axle, said wheel andsaid wall; fixed annular abutment means secured to said end Wall at itsoutboard end; a plurality of pins; means for securing said pins torotate with said wheel; an annular ring; means to secure said annularring to said pins; an abutment means secured to said annular ring,resilient means for urging said last-mentioned abutment means intoengagement with said fixed abutment means; a disk supported by said pinsfor rotation therewith and presenting a pair of friction surfaces withinsaid chamber, said disk being slidably mounted on said pins toaccommodate axial movement of said disk relative to said wheel; a pairof stators disposed on opposite sides of said disk for engagement withrespective friction surfaces, one of said stators being fixed to saidbrake frame, said other stator being suspended around said brake frame;suspension means connecting said other stator to said frame for movementrelative to said frame axially of said assembly; a plurality of powercylinders supported by said brake frame within said chamber andincluding pistons engageable with said other stator at locations inspaced relationship to each other adjacent one side of said other statorand being operable to urge said other stator toward said fixed stator tocompress the friction surfaces of said disk between said stators; aplurality of hydraulic lines interconnecting said cylinders, saidhydraulic lines being Within said chamber; and an inlet port in saidframe communicating with one of said hydraulic lines so that hydraulicaction through said port and said one hydraulic line causes actuation ofall of said pistons of said power cylinders.

4. In a brake arrangement for a rotatable disk the combination of: arotatable disk support; said brake disk 20 splined to said disk supportfor rotation therewith and to permit axial movement of the disk withrespect to the support; a plurality of shoulder screws spacedcircumferentially from each other and extending through openings of saiddisk, said screws being fixed to said disk sup- 25 a compression springin each bore under compression between said support and said disk, saidsprings urging said brake disk against said washers; said brake diskpresenting a pair of opposed friction surfaces; a brake frame; a firststator member supported by said brake frame and having a fixed positionrelative thereto; said first stator member at times engageable with oneof said friction surfaces; a second stator disposed adjacent other ofsaid friction surfaces; means movably connecting the second stator tothe frame for accommodating axial movement of said second stator withrespect to said frame; and power means operable to axially move saidsecond stator to engage said other friction surface and thereby axiallymove said brake disk against the compressive force of said spring, toengage said first mentioned friction surface against said first statormember.

References Cited in the file of this patent UNITED STATES PATENTS854,720 Dawson May 28, 1907 2,260,189 Morrison Oct. 21, 1941 2,771,966Davey Nov. 27, 1956 2,827,132 Buyze Mar. 18, 1958 2,860,738 IohansenNov. 18, 1958 2,911,071 De Gelleke Nov. 3, 1959 FOREIGN PATENTS 538,028Italy Jan. 16, 1956

1. IN AN OFF WHEEL BRAKE ARRANGEMENT FOR A VEHICLE HAVING A WHEEL ANDAXLE ASSEMBLY, THE COMBINATION OF: AN ANNULAR DISK SUPPORT SECURED TOSAID WHEEL FOR ROTATION THEREWITH; A DISK DISPOSED INBOARDLY OF SAIDDISK SUPPORT AND PRESENTING A PAIR OF FRICTION SURFACES; A PLURALITY OFPINS HAVING CORRESPONDING ENDS ATTACHED TO SAID DISK SUPPORT, SAID PINSEXTENDING THROUGH COMPLEMENTARY OPENINGS OF THE DISK TO ACCOMMODATEAXIAL MOVEMENT OF SAID DISK RELATIVE TO SAID SUPPORT AND INTERLOCK THEDISK THEREWITH FOR ROTATION WITH THE WHEEL; A BRAKE FRAME NONROTATABLYMOUNTED AROUND SAID AXLE, INBOARDLY FROM SAID WHEEL, SAID BRAKE FRAMEINCLUDING AN ANNULAR PLATE EXTENDING RADIALLY OUTWARD FROM SAID AXLE,SAID ANNULAR PLATE HAVING A CYLINDRICAL WALL FORMED INTEGRALLYTHEREAROUND AND EXTENDING IN AN OUTBOARDLY DIRECTION THEREFROM; A FIRSTANNULAR RING SECURED AROUND THE OUTBOARD END OF SAID CYLINDRICAL WALL; AFIRST ABUTTING PAD DISPOSED AROUND AND FIXED TO THE OUTBOARD END OF SAIDFIRST ANNULAR RING; A SECOND ANNULAR RING DISPOSED OUTBOARDLY FROM SAIDFIRST ANNULAR RING; A SECOND ABUTMENT PAD SECURED TO THE INBOARD END OFSAID SECOND ANNULAR RING; A PLURALITY OF SCREWS EXTENDING THROUGHAPERTURES IN SAID SECOND ANNULAR RING AND EXTENDING INTO THE INBOARD ENDOF SAID PLURALITY OF PINS; A PLURALITY OF COMPRESSION SPRING MEANSSLEEVED ON RESPECTIVE SCREWS BETWEEN SAID SECOND ANNULAR RING AND SAIDINBOARD END OF SAID PINS FOR URGING SAID SECOND ANNULAR RING INBOARDLYSO AS TO URGE SAID SECOND ABUTMENT PAD INTO ENGAGEMENT WITH SAID FIRSTABUT-